1. Field of the Invention
The present invention relates to a liquid ejection head, liquid ejection apparatus, and image forming apparatus, more particularly to a structure and drive control technology of a liquid ejection head which is suitable for an image forming apparatus such as an inkjet recording apparatus for forming an image on a recording medium by ejecting minuscule liquid droplets.
2. Description of the Related Art
Japanese Patent Application Publication No. 5-38809 discloses an inkjet head which generates ultrasonic wave in ink by driving, at high frequency, a piezoelectric substrate disposed in parallel with a nozzle plate, and ejects mist-like ink (ink mist) from the nozzles. Japanese Patent Application Publication No. 5-38809 further proposes disposition of a concave acoustic lens between the piezoelectric substrate and the nozzle plate in order to focus pressure wave in the vicinity of the nozzles.
However, in the configuration disclosed Japanese Patent Application Publication No. 5-38809, an acoustic lens is required as a device (member) for concentrating ejection energy. Furthermore, not only a high-speed and high-quality print output in recent years, but also maximization of the density of nozzles in a recording head, and further improvement of ejection power are required. In addition, functions controlling the spatter direction or the amount of ejected liquid, and detecting an ejection failure are required to be maximized. In this regard, application to maximization of the function and density is not considered sufficiently in Japanese Patent Application Publication No. 5-38809.